editor's blog
Subscribe Now

A Microphone for Gestures and Canines

A while back, when looking at Elliptic Labs ultrasonic gesture recognition, we mentioned that they were able to do this based on the fact that Knowles microphones worked in the ultrasonic range. But they weren’t willing to say much more about the microphones.

2015-01-07_10_13_31-SPU0410LR5H.pdf_-_Adobe_Reader.pngSo I checked with Knowles; they had announced their ultrasonic microphone back in June. My first question was whether this was just a tweak of the filters or if it was a completely new sensor. And the answer: the MEMS is the same as the one used for their regular audio microphones; they’ve changed the accompanying ASIC. The packaging is also the same. To find similar items you should visit 25pc.com.

The next obvious question is, what is this good for, other than gesture recognition? Things got a bit quieter there – apparently there are some use cases being explored, but they can’t talk about them. So we’ll have to watch for those.

But with respect to the gesture thing, it turns out that, in theory, this can replace the proximity sensor. It’s low enough power that the mic can be operated “always on.” Not only can it detect that something is nearby, in the manner of a proximity sensor, it can go it one better: it can identify what that item is.

From a bill-of-materials (BOM) standpoint, at present you still need to use a separate ultrasonic transmitter, so you’re replacing one component (the proximity detector) with another (the transmitter). But in the future, the speakers could be leveraged, eliminating the transmitter.

It occurred to me, however, that, for this to become a thing, the ultrasonic detection will really need to be abstracted at the OS (or some higher) level, separating it from the regular audio stream. The way things are now, if you plugged a headset into the phone or computer, all the audio gets shunted to the headset, including the ultrasonic signal. Which probably isn’t useful unless you’re trying to teach your dog to use the phone (hey, they’re that intuitive!).

For this really to work, only the audible component should be sent to the headset; the ultrasonic signal and its detection would need to stay in the built-in speaker/mic pair to enable gesture recognition. Same thing when plugging in external speakers.

I’m sure that’s technically doable, although it probably disturbs a part of the system that’s been fixed for years. Which is never fun to dig into. But sometimes you’ve just got to grit your teeth and shed some of the legacy hardware in order to move forward.

You can find out more about Knowles’ ultrasonic microphone here.

 

[Editor’s note: For anyone clicking in through LinkedIn, I changed the title. It was supposed to be light, but, too late, I realized it could be taken as negative, which wasn’t the intent.]

(Image courtesy Knowles)

Leave a Reply

featured blogs
Jun 22, 2021
Have you ever been in a situation where the run has started and you realize that you needed to add two more workers, or drop a couple of them? In such cases, you wait for the run to complete, make... [[ Click on the title to access the full blog on the Cadence Community site...
Jun 21, 2021
By James Paris Last Saturday was my son's birthday and we had many things to… The post Time is money'¦so why waste it on bad data? appeared first on Design with Calibre....
Jun 17, 2021
Learn how cloud-based SoC design and functional verification systems such as ZeBu Cloud accelerate networking SoC readiness across both hardware & software. The post The Quest for the Most Advanced Networking SoC: Achieving Breakthrough Verification Efficiency with Clou...
Jun 17, 2021
In today’s blog episode, we would like to introduce our newest White Paper: “System and Component qualifications of VPX solutions, Create a novel, low-cost, easy to build, high reliability test platform for VPX modules“. Over the past year, Samtec has worked...

featured video

Reduce Analog and Mixed-Signal Design Risk with a Unified Design and Simulation Solution

Sponsored by Cadence Design Systems

Learn how you can reduce your cost and risk with the Virtuoso and Spectre unified analog and mixed-signal design and simulation solution, offering accuracy, capacity, and high performance.

Click here for more information about Spectre FX Simulator

featured paper

What is a Hall-effect sensor?

Sponsored by Texas Instruments

Are you considering a Hall-effect sensor for your next design? Read this technical article to learn how Hall-effect sensors work to accurately measure position, distance and movement. In this article, you’ll gain insight into Hall-effect sensing theory, topologies, common use cases and the different types of Hall-effect sensors available today: Hall-effect switches, latches and linear sensors.

Click to read more

featured chalk talk

Time Sensitive Networking for Industrial Automation

Sponsored by Mouser Electronics and Intel

In control applications with strict deterministic requirements, such as those found in automotive and industrial domains, Time Sensitive Networking offers a way to send time-critical traffic over a standard Ethernet infrastructure. This enables the convergence of all traffic classes and multiple applications in one network. In this episode of Chalk Talk, Amelia Dalton chats with Josh Levine of Intel and Patrick Loschmidt of TTTech about standards, specifications, and capabilities of time-sensitive networking (TSN).

Click here for more information about Intel Cyclone® V FPGAs